| 摘要 |
Methods and apparatus are provided for sensing gases in the environment wherein electrochemical sensing procedures are utilized not only for monitoring ambient continuously for the presence of such gases; but also, for the periodic automatic recalibration and self-adjustment of the sensing instrument, as required, to accommodate changing conditions with time. Such accommodation includes not only changes in the instrument itself, but also changes in the environment affecting the accuracy of the monitoring function. The instrument is connected with a microprocessor, or other information storage or retrieval instrumentation which controls the periodic recalibration by measuring, separately from the monitoring function, the electrochemical response to a sample of the gas being monitored, and by adjusting the subsequent instrument readings to reflect the recalibration. During this recalibration procedure, the instrument can be adjusted to zero reading for accommodating drift, as will be understood. The microprocessor may be adjusted, also, to cause the automatic recalibration of the sensor instrument at preset intervals, as required at the location where it is being used. Thus, the instrument of the invention has the ability to perform a calibration without the need for an operator or calibration gas. The requirement is that the instrument be sensing the gas of interest at the time of calibration.
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